Spring centering crane trolley wheels

ABSTRACT

Crane trolley comprising stub axle mounted wheels which are resiliently spaced from the supporting frame. The rollers may be hollow, and contain oil boxes, bearings, and spacing springs.

=1 tales atent 'lanaka 5] Feb. 29, 1972 [54] SPRING CENTERING CRANETROLLEY WHEELS [72] inventor: Tatsumi Tanaka, 225-4 Zaimo-ku-cho,

Saga, Japan [22] Filed: Feb.3, 1970 [21] Appl. No.: 8,384

[52] US. Cl. ..l05/l63 R, 105/180, 105/181, 244/103 W, 295/1, 295/5,301/2, 301/63 DS [51] Int. Cl ..B60b 17/00, B66c 9/14, B66c 9/16 [58]Field of Search ..l05/l63 R, 178, 180,181; 295/1, 4, 5; 301/263 DS, 64S, 64 WH; 244/103 W [56] References Cited UNITED STATES PATENTS2,626,116 l/l953 Stenby ..244/l03W Germain ..105/180 Norwich 2,861,85011/1958 Nyblom ..lO5/l80 X 765,211 7/1904 Thompson 105/178 X 2,020,42411/1935 Madden et al.. ..295/l 2,556,503 6/1951 Nelson 105/163 R X2,707,443 5/1955 Pope et a1. .....105/180 X 3,257,968 6/1966 Minty et a1..105/163 R Primary Examiner-Arthur L. La Point AssistantExaminer-Howard Beltran Att0rneyHolcombe, Wetherill & Brisebois [57]ABSTRACT Crane trolley comprising stub axle mounted wheels which areresiliently spaced from the supporting frame. The rollers may be hollow,and contain oil boxes, bearings, and spacing springs.

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FIGJO A Women SPRING CENTERING CRANE TROlLlLEY WHEELS SUMMARY OF THEINVENTION This invention relates to trolleys for use in various types ofcranes.

The primary object of the present invention is to provide trolleys forvarious types of cranes in which the pulleys are not subjected to equalwear.

In conventional cranes, such as overhead travelling cranes, jib cranesand post cranes, the trolleys have the following defects. For instance,in the trolleys for overhead traveling cranes, the introduction ofgrease into a bearing is impossible because a driving roller and a freeroller do not have hollow portions, since they are made in one piece.Besides, in the case of overhead travelling cranes, the guide rail maybend even though they are designed to be straight. Consequently eitherthe left front and rear rollers or the right front and rear rollerswhich move back and forth on the guide rail encounter excessiveresistance and excessive wear.

These and other objects and advantages of this invention will be betterunderstood upon consideration of the following detailed description andthe accompanying drawings in which:

FIG. 1 is a top plan view showing a first embodiment of a trolleyaccording to this invention suitable for use in various types of crane;

FIG. 2 is a vertical section taken along the line II-II of FIG.

FIG. 3 is a vertical section taken along the line IIIIII of FIG. 1;

FIG. 4 is a vertical section taken along the line IV-IV of FIG. 1;

FIG. 5 is a top plan view showing a second embodiment of a trolleyaccording to this invention suitable for use in various types of crane;

FIG. 6 is a vertical section taken along the line VI-VI of FIG. 5;

FIG. 7 is a top plan view showing a third embodiment of trolleyaccording to this invention suitable for use in various types of crane;

FIG. 8 is a left side view of the trolley shown in FIG. 7;

FIG. 9 is a right side view of the trolley shown in FIG. 7;

FIG. 10 is a vertical section taken along the line X-X of FIG. 8;

FIG. 11 is a vertical section taken along the line XI-XI of FIG. 8; and

FIG. 12 is a top plan view showing a change in position of the trolleyconstituting the third embodiment of the invention.

Referring now to FIGS. 1-4, the first embodiment of this invention, thefront of which is at the right of these figures, will now be described.

Front shaft 2 and rear shaft 3 are mounted at the front and the rearrespectively of frame 1.

The front roller comprises a left half 4 and a right half 5 mounted onthe shaft 2. A driving gear 6 is attached to the right side of the rightroller-half 5, and the left half 4, the right half 5 and the drivinggear 6 are fastened together by the bolts 7. The roller is provided witha peripheral groove 8, and an oil box 9 is formed inside it. Ballbearings 10 and 11 are mounted on the front shaft 2 on both sides of theoil box 9, and a pair of springs 12 and separator 13 are positionedbetween the bearings 10 and 11. The inner end of each spring 12 bearsagainst a collar 2a fixed to the shaft 2.

The rear roller comprises a left half 15 and a right half 16 connectedtogether by bolts 14 and mounted on the rear shaft 3. This roller isprovided with a peripheral groove 17 and an oil box 18 is fonned insideit. Ball bearings 19 and 20 carried by the rear shaft 3 are mounted onopposite sides of the oil box 18, and a pair of springs 21 and separator22 are positioned between the bearings 19 and 20. The inner end of eachspring 21 bears against a collar 3a fixed to the shaft 3. Bores 23 and24 in the front shaft 2 and rear shaft 3 respectively communicate withthe oil boxes 9 and 18, respectively.

Reference numerals 25 and 26 indicate grease cups which are mounted atthe ends of the bores 23 and 24 respectively.

In this embodiment, since the driving roller to be mounted on the frontside shaft 2 comprises the left half 4, the right half 5 and the drivinggear 6, and the free roller comprises the left half 15 and the righthalf 16, a rather large space is available for the oil boxes 9 and 18 inthe centers of the rollers. Consequently the pairs of ball bearings 10,11, and 19, 20 can be inserted in the oil boxes 9 and 18 respectively sothat the trolley can operate smoothly and last for a long time.

The second embodiment of this invention will now be described. As shownin FIGS. 5 and 6, the front of the device is at the left of the figuresand front shaft 32 and rear shaft 33 are mounted at the front and therear of trolley frame 1. The left roller half 34 and right roller half35, which are biassed together by springs 36 and 36', are mounted on thefront shaft 32. The driving gear 27 is mounted on the right side of theright roller half 35, and the left roller half 34, the right roller half35 and the driving gear 27 are fastened together by bolt 28. This rolleris provided with a peripheral groove 29 and an oil box 30 is formedinside the roller. Ball bearings 31 and 31 which are mounted on thefront side shaft 32 are positioned on both sides of the oil box 30, andspaced by separator 39. A bore 40 which communicates with the oil box 30is provided in the front side shaft 32. Reference numeral 41 indicates agrease cup which is inserted into the end of the bore 40. The rearroller is composed of the two halves 37, 38 and mounted on the shaft 33,and is identical to the front roller, except for the omission of thedriving gear.

In this second embodiment, since the driving roller mounted on the frontshaft 32 comprises the left half 34, the right half 35 and the drivinggear 27, and the free roller comprises the left half 38 and the righthalf 37, a rather large space is available for the oil boxes in thecenter. Consequently the pairs of ball bearings may be inserted in theoil boxes so that the trolley can operate smoothly and last for a longtime. Moreover, since the roller comprising the left half 34 and theright half 35, and the roller comprising the left half 38 and the righthalf 37 respectively can slide slightly to the left or right on theirrespective shafts, against the resistance of the springs 36, 36, therollers can adapt to the condition of the rails. Accordingly, even whenthe rails are not straight but are somewhat uneven, the rollers do notwear excessively.

The third embodiment of this invention will now be described. As shownin FIGS. 7-12, the left front horizontal shaft 62 and left rearhorizontal shaft 63 are mounted at the same height at the front and therear of the upper part of left frame 61. Right front horizontal shaft 62and right rear horizontal shaft 63 are mounted at the front and the rearof the upper part of right frame 61 A drive shaft 44 is mounted at theupper center of the left frame 61, and front horizontal bolt 45 and rearhorizontal bolt 46 connect the lower parts of frames 61 and 61 Thehorizontal bolt 48 passing through the right frame 61' is attached tothe middle of the supporting plate 47, which is attached to the lowerpart of the right frame 61', and the right ends of the left fronthorizontal bolt 45 and the left rear horizontal bolt 46 are located atthe front and rear of the supporting plate 47. Left front flanged roller64 and left rear flanged roller 65 are mounted on the left fronthorizontal shaft 62 and the left rear horizontal shaft 63 respectively,and right front flanged roller 75 and right rear flanged roller 76 aremounted on the right front horizontal shaft 62' and the right rearhorizontal shaft 63' respectively. Left front spring 72 is mountedbetween the left frame 61 and the left front roller 64, and left rearspring 73 is mounted between the left frame 61 and the left rear roller65. Right front spring 72' is provided between the right frame 61' andthe right front roller 75, and right rear spring 73 is provided betweenthe right frame 61' and the right rear roller 76. Driving gear 49provided at the inner end of the drive shaft 44 engages front gear 50and rear gear 51 which are connected to the outside of the left frontroller 64 and left rear roller 65 respectively. Motor 52 is mounted atthe outer end of the driving shaft 44.

In FIGS. 9-11, reference numeral 53 indicates a guide rail. In thisthird embodiment, if the right front roller 75 and right rear roller 76are positioned on the right side of the guide rail 53, the trolleycomprising these pulleys may be put on the guide rail 53 with perfectfreedom of motion. In this case, the left front roller 64 and the leftrear roller 65 are driven on the left side of guide rail 53 through thedrive shaft 44, driving gear 49, the front gear 50, and the rear gear51, by the motor 52. Accordingly the trolley can advance and the rightfront roller 75 and the right rear roller 76 are driven along the rightside of the guide rail 53. When the left front and rear rollers or rightfront and rear rollers are rotated, if the guide rail 53 bends orcurves, for instance, pressure is exerted on the flange of the leftfront roller 64 by the bending of the guide rail 53, and the left frontspring 72 presses against the front portion of the left frame 61 whilebeing compressed. But the width of the left side and right side portionsof the guide rail 53 are equal at all times even if the guide rail bendsor curves. Therefore, a gap is produced between the flange of the rightfront roller 75 and the right portion of the guide rail 53. However, thefront portion of the left frame 61 turns slightly to the left when it isurged to the left. Consequently, as the front portion of the frame 61turns to the left with the motion of the frame 61 and presses againstthe right front roller 75 through the right front spring 72' thuscausing it to move to the left. The flanges of the left front roller 64and the right front roller 75 then come in contact with both sideportions of the guide rail 53 under normal pressure. If the left portionof the guide rail 53 presses against the flange of the left rear roller,the right rear roller 16 moves with it. If the right hand portion of theguide rail 53 presses against the flange of the right front roller 75,the left front roller 64 moves with it. If the right-hand portion of theguide rail 53 presses against the flange of the right rear roller 76,the left rear roller 65 moves with it. Consequently, all four rollers ofthe trolley may press against the side portions of the guide rail 53with normal contacting pressure at all times, in spite of the fact thatthe guide rail 53 bends or curves. The trolley can therefore move backand forth smoothly and abrasion of the four rollers is remarkablydecreased.

What is claimed is:

1. in a trolley for cranes and the like including a support comprising aframe and at least two parallel shafts mounted in said frame, theimprovement which comprises a hollow roller rotatably mounted on eachshaft, each roller comprising two coaxial parts defining a centralrecess, abutment means on each shaft positioned centrally of the recessin the roller carried by that shaft, resilient means in each recessspacing each part of the roller defining that recess from said abutment,and means for admitting a lubricant into said recess.

2. Trolley as claimed in claim 1 comprising bearing means in each recessrotatably mounting each roller on its respective shaft and positionedbetween said resilient means and each part of said roller.

1. In a trolley for cranes and the like including a support comprising aframe and at least two parallel shafts mounted in said Frame, theimprovement which comprises a hollow roller rotatably mounted on eachshaft, each roller comprising two coaxial parts defining a centralrecess, abutment means on each shaft positioned centrally of the recessin the roller carried by that shaft, resilient means in each recessspacing each part of the roller defining that recess from said abutment,and means for admitting a lubricant into said recess.
 2. Trolley asclaimed in claim 1 comprising bearing means in each recess rotatablymounting each roller on its respective shaft and positioned between saidresilient means and each part of said roller.